JPH10318352A - Vehicle final reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a fall of a ring gear of a final reduction device by being brought into contact with a back surface of a meshing portion of the ring gear with a reduction pinion to prevent the ring gear from falling down, a lock nut of an inclination preventing member screwed to a differential carrier. At the time of tightening, the tilt preventing member is prevented from rotating together, and is accurately and easily fixed on the differential carrier. SOLUTION: A first screw shaft portion screwed to a differential carrier, a second screw shaft to which a lock nut is screwed, and coaxially formed between the first and second screw shaft members. The engaging portion having a non-circular cross section is provided. on the other hand,
A recess is formed in the seat surface of the lock nut at the outer open end of the screw hole of the differential carrier. After screwing the inclination preventing member to the differential carrier and adjusting it to a regular mounting position, a locking member is fitted into the engaging portion and inserted into the concave portion, whereby relative rotation of the inclination preventing member with respect to the differential carrier is adjusted. It is prohibited to prevent the inclination preventing member from rotating when the lock nut is tightened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle final reduction gear suitable for use in vehicles such as trucks and buses.

[0002]

2. Description of the Related Art An example of the structure of a final reduction gear employed in a conventional large truck or the like will be described with reference to a sectional view of FIG. In the drawing, reference numeral 10 generally indicates a final reduction gear, and the final reduction gear 10 includes a differential carrier 12 which forms a housing or a casing containing a reduction gear and a differential gear device described later.

A bearing retainer 14 is removably mounted on the differential carrier 12 by bolts 16. The bearing retainer 14 is provided with a shaft portion 18b on the large end side of a reduction pinion 20 having a hypoid gear 18a. It is rotatably supported via an inner bearing 22 and an outer bearing 24 formed of bearings. A companion flange 26 is spline-connected to an end of the shaft portion 18b of the reduction pinion 20 protruding outside the differential carrier 12, and the companion flange 26 is
It is connected to a crankshaft of an engine which is a motor of the vehicle via a propeller shaft (not shown).

A shaft portion 18c cooperating with the shaft portion 18b is coaxially protruded from the small end of the reduction pinion 20, and the coaxial portion 18c is rotated by a pilot bearing 28 provided on the differential carrier 12. It is freely supported. A differential case 32 is rotatably supported on the differential carrier 12 via left and right side bearings 30. The differential case 32 includes a left case 32L and a right case 32R that are divided into left and right parts. The left and right cases 32L and 32R are integrally connected by a plurality of bolts 34.

A plurality of bolts 3 are attached to the left case 32L.
6, a large-diameter ring gear 38 is fixed. The ring gear 38 has hypoid teeth meshing with the hypoid gear 18a of the reduction pinion 20, and constitutes a reduction gear device together with the reduction pinion 20. In the differential case 32, left and right differential gears 40L and 40R are provided.
And a differential gear device comprising a plurality of differential pinions 44 rotatably supported on a pinion spider 42 and meshing with the differential gears 40L and 40R, respectively. The differential gears 40L and 40R are shown The axles that drive the left and right driving wheels are connected.

Further, an inclination preventing member 48 of the ring gear 38 is screwed onto the differential carrier 12 at a position facing the meshing rear surface 46 of the ring gear 38 which meshes with the reduction pinion 20.
The inclination preventing member 48 is adjustably threadedly engaged with the differential carrier 12 so as to maintain a predetermined minute interval between the tip end portion 50 and the meshing portion rear surface 46 of the ring gear when no load is applied. After that, it is fixed by the lock nut 52.

While the vehicle is running, the reduction pinion 20 is driven by the driving force of the engine, and the ring gear 38 meshing with the hypoid gear 18a of the reduction pinion is reduced and driven integrally with the differential case 32. The rotation of the differential case 32 is transmitted to left and right differential gears 40L and 40R by the action of a well-known differential gear device, and further transmitted to left and right drive wheels via left and right axles.

While the vehicle is running, the reduction pinion 20
When the transmission torque of the ring gear 38 becomes extremely large, the meshing reaction force generated at the meshing portion of the ring gear 38 with the reduction pinion 20 increases, and the ring gear 3 is caused by the meshing reaction force in the lateral direction, that is, the leftward direction in FIG.
The meshing portion 8 is pushed to the left and tilts, that is, falls.

[0009] If the ring gear 38 is greatly inclined, meshing with the reduction pinion 20 will not be performed properly, resulting in poor contact with the teeth. This will cause abnormal wear on the tooth surface and breakage of the teeth. In such a case, in the illustrated final reduction gear 10, an inclination preventing member 48 is screwed to a portion of the differential carrier 12 facing the meshing portion rear surface 46 of the ring gear 38, and the ring gear 38 is engaged with the meshing reaction force under heavy load. In this case, the tip end 50 of the inclination preventing member 48 is
6 to prevent the gear from tilting further.

When the transmission torque of the reduction pinion 20 and the ring gear 38 is large and the inclination of the ring gear 38 reaches a set value, the tip of the inclination prevention member 48 contacts the rear surface 46 of the meshing portion. Is relatively small during normal operation, a predetermined value is set between the distal end portion 50 and the meshing portion rear surface 46 in a no-load state so that the distal end portion 50 and the meshing portion rear surface 46 do not come into contact with each other. It must be accurately positioned with respect to the differential carrier 12 so that the minute gap t is formed.

In order to properly position the anti-tilt member 48 with respect to the differential carrier 12, the conventional apparatus uses a screw of the anti-tilt member 48, as shown in a partially enlarged sectional view of FIG. Shaft 48a
To the corresponding screw holes 5 of the differential carrier 12
After screwing to 4, the tip end portion 50 comes into contact with the meshing portion rear surface 46 of the ring gear 38 by applying a tool such as a wrench to a small-diameter bolt head 48b provided at the base end of the screw shaft portion 48a. The screw shaft portion 48a is screwed back until the screw shaft portion 48a is screwed back by a preset rotation angle to form a set gap t between the distal end portion 50 and the meshing portion rear surface 46 of the ring gear. An operation has been performed in which a lock nut 52 is screwed into the base end side to fix the inclination preventing member 48 at that position.

When the lock nut 52 is tightened, a tightening torque is specified to prevent loosening.
An operation of fitting the socket 56 to the lock nut 52 and rotating the socket 56 by the torque wrench 58 is performed. However, when the lock nut 52 is tightened, the screw shaft portion 48a sometimes rotates together. If the screw shaft portion 48a rotates, the set gap t is not maintained and an error proportional to the rotation angle is generated. When the socket 56 is fitted into the lock nut 52, the base end of the inclination preventing member 48 is covered with the socket 56 and cannot be visually recognized. Therefore, the presence or absence of the co-rotation cannot be detected. However, it is practically difficult to properly secure the set gap t, and there is a problem that the possibility that the tightening of the lock nut 52 causes an error is high.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. When the above-described tilt preventing member is screwed into a differential carrier and positioned and fixed at a predetermined position by a lock nut, the tilt preventing member is prevented. It is an object of the present invention to provide a final reduction gear for a vehicle in which the above-mentioned rotation of the member is reliably prevented, and the inclination preventing member can be accurately and easily fixed at a predetermined position.

[0014]

In order to achieve the above object, the present invention provides a reduction pinion rotatably driven by a driving force from a prime mover and a reduction pinion rotatably supported by a differential carrier and meshed with the reduction pinion. And a ring gear that transmits driving force to the axle via a differential gear device, and is screwed to the differential carrier to prevent the ring gear from falling down by contacting the rear end of the ring gear with the meshing portion of the ring gear. An engaging portion having a non-circular cross section is formed between the bolt head provided at the base end portion and the first screw shaft portion screwed to the differential carrier; Anti-inclination member having a second screw shaft portion provided between it and a differential carrier of the anti-inclination member A locking member interposed between the engaging portion and the differential carrier for inhibiting rotation of the inclination preventing member after adjusting a screwing position with respect to the locking member; and a locking member screwed to the second screw shaft portion to prevent rotation of the locking member. And a lock nut for fixing the inclination preventing member to the differential carrier after the interposition.

According to the above construction, the inclination preventing member is screwed into the differential carrier and adjusted to the set screwing position, and then the locking member is interposed in the engaging portion having the non-circular cross-section, thereby providing the inclination preventing member. Relative rotation with respect to the differential carrier is prohibited, so that when the lock prevention member is fixed to the differential carrier by the lock nut, the tilt prevention member is prevented from rotating together and is correctly fixed to the set screw position.

In the present invention, the lock member has an annular portion externally fitted to the engagement portion so as to be relatively non-rotatable, and a claw projecting outward from the annular portion, and the lock of the differential carrier is provided. It is preferable that a concave portion for accommodating the lock member so as not to rotate is formed on the nut seat surface. With this configuration, when screwing the lock nut to the tilt prevention member, during normal tightening work, the lock member is housed in the concave portion of the lock nut seat surface of the differential carrier, so that the rotation of the tilt prevention member can be prevented. It is forbidden. In addition, when the lock member escapes from the concave portion for any reason during the work of tightening the lock nut, the claw portion of the lock member is caught between the lock nut and the bearing surface of the differential carrier. ,
After the end of the tightening operation, it is easily found that the tightening operation was not performed normally.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to FIGS. (Note that FIG.
Members that are substantially the same as or correspond to those of the conventional final deceleration device described with reference to FIG. 8 are denoted by the same reference numerals, and redundant description is omitted. As shown in the enlarged sectional view of FIG. 1 corresponding to the attachment portion of the inclination preventing member indicated by the arrow I in FIG.
A first screw shaft portion 48a of the inclination preventing member 48 is screwed into a screw hole 54 provided at a portion of the differential carrier 12 facing the back surface 46 of the meshing portion. Between the back 46
In the no-load state, a preset gap t is formed. The tip portion 50 is, for example, a tilt preventing member 48.
60 made of anti-friction alloy attached to one free end of
Is formed by the end face of. In place of the cap 60, a ceramic pad or the like having high wear resistance can be used.

As shown in the plan view of FIG. 4 and the front view of FIG. 5, a lock nut 52 is screwed to the base portion of the first screw shaft 48a. A second screw shaft portion 48c is provided coaxially, an engagement portion 48d having a non-circular cross section is formed between the first screw shaft 48a and the second screw shaft portion 48c, and the second screw shaft portion 48c is formed. At the end opposite to the engaging portion 48d of the shaft portion 48c, the inclination preventing member 48 is provided with a screw hole 54 of the differential carrier 12.
Is formed with a bolt head 48b for screwing the bolt.

In the illustrated example, the engaging portion 48d having a non-circular cross section is formed as 12 points having 12 apexes. However, the engaging portion 48d may have any non-circular cross section such as a regular hexagon, a regular octagon, or a serration or spline cross section. An engagement portion having a cylindrical cross section can be employed. The outer diameter of the second screw shaft portion 48c is smaller than the outer diameter of the engaging portion 48d.

On the other hand, the differential carrier 1
2, the seat surface 62 against which the lock nut 52 contacts
As shown in FIG. 3, an annular portion 64a formed coaxially with the screw hole 54, and one or more radial recesses 6 extending radially outward from the annular portion 64a.
4b is provided.

The lock member 66 shown in FIG. 6 is accommodated in the recess 64. The lock member 66 has an annular portion 66a provided with 12 points of engagement holes 68 having 12 apexes which can be fitted to the engagement portions 48d on its inner periphery, and a radial direction on the outer periphery of the annular portion 66a. And a claw portion 66b protruding and extending outward, preferably,
It is formed by stamping a steel plate with a press.

When assembling the inclination preventing member 48 to the differential carrier 12, first, the first screw shaft 4
8a is screwed into the screw hole 54, a tool such as a wrench or a power tightening device is applied to the bolt head 48b, and the tool is tightened until the tip 50 comes into contact with the meshing rear surface 46 of the ring gear 38, and then the required rotation is performed. By unscrewing by an angle, a set gap t is formed between the distal end portion 50 and the meshing portion rear surface 46.

Next, the lock member 66 is connected to the bolt head 48b.
From the side to move in the axial direction, and its annular portion 66a
Of the concave portion 64 provided on the lock nut seat surface 62
a, the 12-point engaging hole 68 is fitted to the 12-point engaging portion 48d of the inclination preventing member 48, and the claw portion 66b is fitted to the radially outwardly extending recess 64b of the concave portion 64. Let it. The engaging hole 68 and the engaging portion 48d
, The relative rotation between the inclination preventing member 48 and the lock member 66 is prohibited, and the claw 66b and the recess 6 are prevented from rotating.
4b, the relative rotation between the lock member 66 and the differential carrier 12 is prohibited, and as a result, the inclination preventing member 48 is moved to the differential carrier 1
2 is locked non-rotatably.

Subsequently, the lock nut 52 is screwed into the second screw shaft portion 48c of the inclination preventing member 48, and the socket 56 and the torque wrench 5 are screwed in the same manner as in the conventional working method shown in FIG.
By tightening the lock nut 52 using 8, the inclination preventing member 48 can be accurately and easily fixed to the differential carrier 12 while prohibiting swiveling.

During the tightening operation of the lock nut 52, the lock member 66 moves outward in the axial direction for some reason, so that the claw 66b comes out of the recess 64b and the recess 64b.
If the lock nut 52 is tightened in a state where the lock nut 52 is not aligned with the lock nut 52,
Since the claw portion 66b is caught between the lock nut 52 and the seat surface 62 of the differential carrier 12, a gap is formed, so that an operator can easily find out that the lock nut 52 was not properly tightened. Therefore, the operator only has to loosen the lock nut 52 once, insert the lock member 66 into the proper position, and perform the tightening again.

In the illustrated embodiment, the engaging portion 48d of the inclination preventing member 48 has 12 points, and the engaging hole 68 of the cooperating lock member 66 has 12 points. The hole 68 may be a hexagonal or other polygonal hole that fits into the 12 points of the engagement portion 48d so as to be relatively non-rotatable. Further, the engagement portion 48d and the engagement hole 6
8 can be serration shafts and serration holes that fit non-rotatably with each other, or polygonal shafts and cooperating polygonal holes.

Further, the engagement hole 68 of the lock member 66 is provided.
Is fitted to the engaging portion 48d of the inclination preventing member 48, and when the claw portion 66b is fitted to the recess 64b of the concave portion 64, the claw portion 66b and the recess 64b are not necessarily aligned, and both are fitted. For this reason, it is sometimes necessary to align the claw 66b, the recess 64b, and the recess 64b by slightly rotating them after positioning the inclination preventing member 48 first. Since the rotation angle is small, the small amount of change that occurs in the set gap t is conventionally limited to the inclination preventing member 4 when the lock nut 52 is tightened.
Since the amount of change in the gap t caused by a large rotation angle when the 8 rotates with the motor 8 is much smaller, there is no problem in practical use.

In order to further reduce the relative rotation angle for aligning the claw 66b and the recess 64b,
The engagement hole 68 and / or the engagement portion 48d of the lock member 66
Is preferably a regular polygon having 12 or more sides as shown in the figure, or a serration or a spline having a pitch smaller than 12 points, whereby the amount of change in the set gap t can be made extremely small. . Therefore, in this specification, the lock member 66
With respect to the expression that the rotation of the inclination preventing member 48 is inhibited by engaging with the engaging portion 48d after adjusting the screwing position of the inclination preventing member 48 to the differential carrier 12, the claw portion 66b and the recess 64b This does not include the rotation of the inclination preventing member 48 at a minute angle or the minute relative rotation in the range of the play of the fitting portion for aligning and fitting with each other, and prohibits the relative rotation at a large rotation angle such as the co-rotation. Should be interpreted as meaning.

[0029]

As described above, the final reduction gear for a vehicle according to the present invention includes a reduction pinion rotatably driven by a driving force from a prime mover, and a reduction pinion rotatably supported by a differential carrier. A ring gear that is driven by meshing and transmits driving force to the axle via a differential gear device, and a screw is screwed onto the differential carrier to prevent the ring gear from falling down by abutting its tip against the rear surface of the meshing portion of the ring gear. An engaging portion having a non-circular cross section is formed between the bolt head provided at the base end portion and the first screw shaft portion screwed to the differential carrier. A tilt prevention member provided with a second screw shaft between the head and a differential carrier of the tilt prevention member A locking member interposed between the engaging portion and the differential carrier to prohibit rotation of the inclination preventing member after the screwing position is adjusted; and a locking member screwed to the second screw shaft portion. And a lock nut for fixing the inclination prevention member to the differential carrier after the interposition.When the inclination prevention member is screwed to the differential carrier and fixed at a predetermined position by the lock nut, It is possible to reliably prevent the tilt preventing member from rotating together, and to accurately and easily fix the tilt preventing member at the predetermined position. As a result, when no load is applied, the tip of the tilt preventing member is engaged with the meshing portion of the ring gear. There is an advantage that a preset interval can be correctly formed with the back surface.

Further, in the above invention, the lock member has an annular portion which is fitted to the engagement portion so as to be relatively non-rotatable, and a claw portion which projects outward from the annular portion. The lock nut seating surface has a concave portion for accommodating the lock member in a non-rotatable manner, so that the lock member has a simple structure and is easy to assemble. When the lock nut is not properly tightened after escaping from the position, there is an advantage that the operator can easily find out and perform necessary processing.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing a preferred embodiment of the present invention.

FIG. 2 is a front view as viewed from the direction of arrow II in FIG. 1;

FIG. 3 shows a tightening seat surface 6 of the lock nut 52 in FIG.
2 is a front view of FIG.

FIG. 4 is a plan view showing an inclination preventing member 48 in FIG. 1;

FIG. 5 is a front view as viewed from the direction of arrow V in FIG. 4;

FIG. 6 is a plan view of a lock member 66 in FIG.

FIG. 7 is a sectional view showing a conventional final reduction gear for a vehicle.

8 is a cross-sectional view showing an operation mode of fixing the inclination preventing member 48 in FIG. 7 by tightening a lock nut 52. FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Final reduction gear, 12 ... Differential carrier, 20 ... Reduction pinion, 32 ... Differential case, 38 ... Ring gear, 40L and 40R ...
Differential gear, 42 ... pinion spider, 4
Reference numeral 4: Differential pinion, 46: Back surface of the meshing portion of the ring gear, 48: Anti-tilt member, 48a: First screw shaft portion, 48b: Bolt head, 48c: Second screw shaft portion, 48
d: engaging portion, 50: tip of the inclination preventing member, 52: lock nut, 54: screw hole, 56: socket, 58: torque wrench, 62: seat surface, 64: concave portion, 64a: annular portion,
64b: recess, 66: locking member, 66a: annular portion,
66b ... nail part.

Claims (2)

[Claims] A reduction pinion rotatably driven by a driving force from a prime mover; a reduction pinion rotatably supported by a differential carrier and driven by meshing with the reduction pinion; and a driving force applied to an axle via a differential gear device. And a screw head that is screwed to the differential carrier so as to prevent the ring gear from falling down by contacting the front end portion with the rear surface of the meshing portion of the ring gear, and a bolt head provided at a base end portion and the differential gear. An anti-tilt in which an engagement portion having a non-circular cross section is formed between the first screw shaft portion screwed to the carrier and a second screw shaft portion is further provided between the engagement portion and the bolt head. Prohibits rotation of the tilt-prevention member after adjusting the screwing position of the member and the tilt-prevention member to the differential carrier A lock member interposed between the engagement portion and the differential carrier, and the tilt prevention member fixed to the differential carrier after the lock member is interposed by being screwed to the second screw shaft portion. A final reduction gear for a vehicle, comprising: 2. The lock member according to claim 2, wherein the lock member has an annular portion externally fitted to the engagement portion so as to be relatively non-rotatable, and a claw portion projecting outward from the annular portion, and the lock nut seat of the differential carrier. 2. The final reduction gear for a vehicle according to claim 1, wherein a concave portion is formed on a surface of the lock member so as to accommodate the lock member so as not to rotate.